Growing up, I read a lot of mythology. I took classes on it, too (as do many gamers and fantasy writers). So, I base a lot of the concepts and names in my stories on mythology. Of course, the problem is, a LOT of people do that. Video game designers, film makers, other writers. When you use something that’s appeared in popular culture, you run the risk of being told “You totally ripped that off XYZ.”

I read a lot. I have all my life. It’s really difficult to keep all that subconscious knowledge from influencing me in some way. I would argue that to do so would not only be counter-productive, but would make my life and my writing devoid of creation. Explaining a new concept in writing, to an audience who has never heard of it, can be very difficult. If it’s truly new and unique, it can be equally difficult just to write about. Using ideas, concepts, and descriptions that are somewhat familiar to an audience already can help them visualize it in a very quick, efficient way. It’s a risk every author takes. One can be influenced without even realizing it. One just has to trust that their editors and beta readers will point out anything too overt. That’s why we go through the process.

Take World Trees, for example. They are linked with things like the Tree of Life, Yggdrasil, etc. The idea has been around for millenia. Azeroth, the world of World of Warcraft also has world trees, of a sort. So did the film, Avatar (Hometree). It’s not new, but I guarantee you someone, somewhere will criticize me for using it in my novel, Wings of Twilight and say “You ripped off World of Warcraft!” It’s a short reference to something that isn’t even seen in the story.

“He saw their World Tree, Syl’drasil, once, from a great distance, but never cared to venture deep enough into the forest to find it. The World Tree was over a mile high, near half that in diameter and as old as the world itself, if one believed the stories.”

—Wings of Twilight

Another example are devils. Demons, devils, whatever you want to call them. Most depictions of them have some similarities. Common attributes include horns, red skin, resistance to fire, wings–usually leathery or bat wings, sharp teeth. I have never read a description about an entity specifically called a demon or devil that didn’t include one of those. Like Poseidon’s trident, or Zeus’s lightning bolt, those attributes help an audience make an immediate connection and help them identify what is is they’re reading about or seeing.

It’s not a rip off, it’s a tool. Readers will enjoy your writing more if you make it easy for them to visualize and identify with what you’re describing. If they have to analyze every sentence, stopping to look up words or research concepts, chances are, they’re not going to finish your book.